package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.Voucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.BeanUtils;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;



    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

//    private BlockingQueue<VoucherOrder> orderTasks=new ArrayBlockingQueue<>(1024*1024);
//
//    private static final ExecutorService SECKILL_ORDER_EXECUTOR= Executors.newSingleThreadExecutor();
//
//    @PostConstruct
//    private void init(){
//        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
//    }
//
//
//
//    private class VoucherOrderHandler implements Runnable{
//
//        @Override
//        public void run() {
//            while(true){
//                try {
//                    //1.获取队列中的队列信息
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    //创建订单
//                    handlerVoucherOrder(voucherOrder);
//                } catch (InterruptedException e) {
//                    log.info("处理订单异常",e);
//                }
//            }
//        }
//    }

    private class VoucherOrderHandler implements Runnable{
        String queueName = "stream.orders";
        @Override
        public void run() {
            while(true){
                try {
                    //1.获取消息队列中的队列信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAM stream.orders >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.latest())
                    );
                    //2.1判断消息是否获取成功
                    if (list==null || list.isEmpty()) {
                        //2.1 如果获取失败，说明没有消息，继续下一次循环
                        continue;
                    }
                    //3 解析list中的消息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    //3.如果获取成功，可以下单
                    handlerVoucherOrder(voucherOrder);
                    //Ack确认 ACK stream.orders g1 id;
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());

                } catch (Exception e) {
                    log.info("处理订单异常",e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while(true){
                try {
                    //1.获取pending-list中的队列信息 XREADGROUP GROUP g1 c1 COUNT 1 STREAM streams.order 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    //2.1判断消息是否获取成功
                    if (list==null|| list.isEmpty()) {
                        //2.1 如果获取失败，说明pending-list没有异常消息，结束循环
                        break;
                    }
                    //3 解析list中的消息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    //3.如果获取成功，可以下单
                    handlerVoucherOrder(voucherOrder);
                    //Ack确认 ACK stream.orders g1 id;
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());

                } catch (Exception e) {
                    log.info("处理pending-list订单异常",e);
                }
            }

        }
    }

    private void handlerVoucherOrder(VoucherOrder voucherOrder) {

        Long userId = voucherOrder.getUserId();
        //创建锁对象
        SimpleRedisLock simpleRedisLock = new SimpleRedisLock("order" + userId, stringRedisTemplate);
        try {
            //获取锁
            boolean isLock = simpleRedisLock.tryLock(500);
            //判断是否获取锁成功
            if (!isLock) {
                //获取失败，返回错误信息或者重试
                log.info("服务器繁忙，请稍后再试");
            }
            proxy.createVoucherOrder(voucherOrder);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }finally {
            //释放锁
            simpleRedisLock.unlock();
        }

    }

    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        UserDTO user = UserHolder.getUser();
        Long userId = user.getId();
        long orderId = redisIdWorker.nextId("order");

        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(),String.valueOf(orderId)
        );
        int r = result.intValue();
        //2.判断脚本是否为零
        if (r != 0) {
            //2.1 不为零，代表没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
//        //2.2 为零，有购买资格，把下单信息保存到阻塞队列里去
//        //2.3创建订单
//        VoucherOrder voucherOrder = new VoucherOrder();
//        //2.4订单id
//        voucherOrder.setId(orderId);
//        //2.5用户id
//        voucherOrder.setUserId(userId);
//        //2.6代金券id
//        voucherOrder.setVoucherId(voucherId);
//        // TODO 保存到阻塞队列里去
//        orderTasks.add(voucherOrder);
        //3.获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        //4.返回订单id
        return Result.ok(orderId);
    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder){

        // 5 todo 一人一单
        Long userId = voucherOrder.getUserId();


        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        if (count > 0) {
            //用户已经购买过
            log.info("用户已购买一次");
        }
        //6.扣减订单
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0).update();

        if (!success) {
            //扣减失败
            log.info("库存不足");
        }
        save(voucherOrder);

    }
}
/*
    @Override
    public Result seckillVoucher(Long voucherId) {
        //1.查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        //2.判断秒杀是否开始
        LocalDateTime beginTime = voucher.getBeginTime();
        if (beginTime.isAfter(LocalDateTime.now())) {
            // 尚未开始
            return Result.fail("活动尚未开始");
        }
        //3.判断秒杀是否已经结束
        LocalDateTime endTime = voucher.getEndTime();
        if (endTime.isBefore(LocalDateTime.now())) {
            // 已经结束2
            return Result.fail("活动已经结束");
        }
        //4.判断库存是否充足
        if (voucher.getStock()<1) {
            // 库存不足
            return  Result.fail("库存不足");
        }
        //创建锁对象
        Long userId = UserHolder.getUser().getId();
        SimpleRedisLock simpleRedisLock = new SimpleRedisLock("order" + userId, stringRedisTemplate);
        try {
            //获取锁
            boolean isLock = simpleRedisLock.tryLock(500);
            //判断是否获取锁成功
            if (!isLock) {
                //获取失败，返回错误信息或者重试
                return Result.fail("服务器繁忙，请稍后再试");
            }
            //获取代理对象
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }finally {
            //释放锁
            simpleRedisLock.unlock();
        }
       *//* Long userId = UserHolder.getUser().getId();
        synchronized (userId.toString().intern()) {
            // todo 获取代理对象（事务）
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            //8.返回订单id
            return proxy.createVoucherOrder(voucherId);
        }*//*
    }

    @Transactional
    public  Result createVoucherOrder(Long voucherId){

        // 5 todo 一人一单
        Long userId = UserHolder.getUser().getId();


            int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            if (count > 0) {
                //用户已经购买过
                return Result.fail("用户已购买一次");
            }
            //6.扣减订单
            boolean success = seckillVoucherService.update()
                    .setSql("stock = stock - 1")
                    .eq("voucher_id", voucherId).gt("stock", 0).update();

            if (!success) {
                //扣减失败
                return Result.fail("库存不足");
            }
            //7.创建订单
            VoucherOrder voucherOrder = new VoucherOrder();
            //7.1订单id
            long orderId = redisIdWorker.nextId("order");
            voucherOrder.setId(orderId);
            //7.2用户id
            voucherOrder.setUserId(userId);
            //7.3代金券id
            voucherOrder.setVoucherId(voucherId);
            save(voucherOrder);

            return Result.ok(userId);

    }
}*/
